Fix build with python 2.6

* Packages cannot be executed
* '.format' needs the index of the argument

(Reported in https://github.com/Homebrew/homebrew/issues/35616)

Makefile

@@ -63,7 +63,7 @@ youtube-dl: youtube_dl/*.py youtube_dl/*/*.py
 	chmod a+x youtube-dl
 
 README.md: youtube_dl/*.py youtube_dl/*/*.py
-	COLUMNS=80 python -m youtube_dl --help | python devscripts/make_readme.py
+	COLUMNS=80 python youtube_dl/__main__.py --help | python devscripts/make_readme.py
 
 CONTRIBUTING.md: README.md
 	python devscripts/make_contributing.py README.md CONTRIBUTING.md

devscripts/make_supportedsites.py

@@ -23,12 +23,12 @@ def main():
 
     def gen_ies_md(ies):
         for ie in ies:
-            ie_md = '**{}**'.format(ie.IE_NAME)
+            ie_md = '**{0}**'.format(ie.IE_NAME)
             ie_desc = getattr(ie, 'IE_DESC', None)
             if ie_desc is False:
                 continue
             if ie_desc is not None:
-                ie_md += ': {}'.format(ie.IE_DESC)
+                ie_md += ': {0}'.format(ie.IE_DESC)
             if not ie.working():
                 ie_md += ' (Currently broken)'
             yield ie_md